The article “Development of an Adaptive Workload Management System Using the Queuing Network-Model Human Processor (QN-MHP),” C. Wu et al, IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS, VOL. 9, No. 3, September 2008 describes a queuing network-model human processor for an adaptive workload management system (AWMSs) is known. The risk of vehicle collisions significantly increases when drivers are overloaded with information from in-vehicle systems. Increasingly more in-vehicle information and entertainment systems, e.g. navigation aids, mobile phones, e-mail, web browsers, vehicle-to-vehicle communication systems, and traffic information displays are being used in vehicles. One of the solutions to this problem is developing AWMSs to dynamically control the rate of messages from these in-vehicle systems. The driver's workload is estimated in several driving situations. A message controller determines the optimal delay times between messages and dynamically controls the rate of messages presented to the driver. The rate of messages is adapted to the driving conditions, e.g. speed and curvatures, and driver characteristics, e.g., age. AWMSs collect current driving information, such as steering wheel angle and lane position, and then use computational algorithms to directly estimate the current workload of the driver. To reduce the driver's workload, messages from in-vehicle systems are suppressed or messages are redirected into a voice mailbox when the driver's estimated mental workload is high. Multitasking information in driving is typically presented in a multimodal format: either through the visual (e.g., looking at a map or a display of a navigation system) or the auditory modality (e.g., listening to messages from cellular phones or warning systems). Drivers read directions for and the distance to the next turn (maneuver point) from the display (perceptual processing), perform mental calculations to decide whether and when to switch to a different lane (cognitive processing), and possibly engage the turning signal and turn the steering wheel (motor processing). The level of driver workload and performance can be estimated based on road situations, drivers' age, message properties from the in-vehicle systems change in terms of modalities, message difficulty, and motor execution time. Absolute and differential thresholds of the simulated workload can be set to determine the optimal design of the messages and whether the proposed design can produce a workload that is higher than the “redline”. Global Positioning Systems (GPS) can also be used to measure road curvatures and speed on the next road section so that the AWMS can estimate the driver workload a few seconds in advance. The focus of AWMS is to reduce driver workload. It is suitable for non-urgent messages of in-vehicle systems when delaying messages for a few seconds is allowable, e.g., messages from e-mail systems and messages related to traffic congestion. For urgent messages that require immediate driver response, e.g. forward collision warning messages, no extra delays are allowed. Algorithms can manage messages with different priorities, including the order and length of these messages. Further driving conditions, such as traffic density, intersections, road curvature in the next few seconds, route planning and selections, and weather conditions may be added.
The object of the invention is to improve a system for a vehicle.
Said object is attained by a system with the features of independent claim 1. Advantageous refinements are the subject of dependent claims and included in the description.
Therefore, a system for a vehicle is provided. The system has a head-up display and a circuit, whereby the circuit is connected to the head-up display.
The head-up display is configured to project an image onto the vehicle's front windshield or onto a separate combiner.
The circuit is configured to output image data to the head-up display in order to generate the image. The image data have a set of objects which include messages for the user.
The circuit is configured to determine the user's workload level based on a set of driving conditions.
The circuit is configured, based on the level, to switch between at least one first workload mode and a second workload mode. The level assigned to the second workload mode is higher than the level assigned to the first workload mode.
The circuit is configured in the second workload mode to reduce at least one object of the set, which is output in the first workload mode.
Tests by the applicant have shown that a plurality of information can be displayed simultaneously to the driver in high resolution by the head-up display, without the driver having to look away from the traffic ahead to perceive the information. The driver's workload could be significantly reduced by a specific configuration of an adaptive workload management system by the intelligent reduction of the objects.
The invention further has the object of providing an improved method for controlling a head-up display.
Said object is attained by the method with the features of independent claim 7. Advantageous refinements are included in the description.
Therefore, a method for controlling a head-up display for a vehicle is provided. The method has the steps:
Projecting an image onto a front windshield of the vehicle or onto a separate combiner by means of the head-up display.
Outputting image data from a circuit to the head-up display to generate the image, whereby the image data have a set of objects that include messages for the user. The circuit may be connected to the head-up display.
Determining the user's workload level based on a set of driving conditions by means of the circuit.
Switching between at least one first workload mode and a second workload mode, based on the level, whereby the second workload mode is assigned a higher workload level than the first workload mode.
Reducing at least one object of the set in the second workload mode, wherein said at least one object of the set is output in the first workload mode.
The refinements described hereinafter relate to both, the system and the control method.
According to one embodiment, to reduce the at least one object the circuit may be configured to fade out the object and/or to make the object in the image smaller and/or to increase the transparency of the object and/or to move the object within the image away from a central position into a predetermined area. The object may be moved from a position in the main viewing direction of the driver towards a boundary, so that the object is not disturbing the driver while viewing the traffic in front. An uncritical area, the object may be moved to, is a lower edge of the image area, so that the drivers may see the object virtually before the engine bonnet of the vehicle.
According to one embodiment, the circuit may be configured during or after the reduction to output the message associated with the object by means of another object in another display different from the front windshield.
According to one embodiment, the circuit may be configured to identify an input by the user. The circuit may be configured, based on the input, to start an application program, whereby the object is associated with the application program.
According to one embodiment, the circuit may be configured to prioritize the objects. The circuit may be configured to reduce first the object with the lowest priority in the second workload mode.
According to one embodiment, the circuit may be configured to switch to a warning mode. The circuit may be configured to reduce at least one of the objects of the set in the warning mode and to output at least one warning object at least temporarily in the image data.
The previously described embodiment variants are especially advantageous both individually and in combination. In this regard, all embodiment variants can be combined with one another. Some possible combinations are explained in the description of the exemplary embodiments shown in the figures. These possible combinations of the embodiment variants, depicted therein, are not definitive, however.